As barragens de enrocamento com face de concreto (BEFC) têm sido construídas com freqüência crescente em todo mundo. Apesar disso, os critérios de. Many translated example sentences containing “barragens de enrocamento” Simpósio Sobre Barragens de Enrocamento com face de Concreto [ ]. 15 out. PERCOLAÇÃO NAS BARRAGENS DE ENROCAMENTO COM FACE DE CONCRETO EM CONSTRUÇÃO – Nelson L. de S. Pinto.
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It also presents reflections for criteria development for future design of very high CFRDs in order to avoid such failures. It must be pointed out that this feature is critical on abutments. Help Center Find new research papers in: This model must be dynamic, not only to define the zoning of the embankment as well as future adjustments, in function of the monitoring during the construction.
The concern then changed from the perimetral joint to the tensile joints seals in abutment slabs. Thus, progressive modifications were introduced in the CFRD design, among them: In other cases, leakages occurred by the failure of water stops due to excessive deformation. These suggestions should be enrocamenot for each case.
This model doesn’t consider the joints between the slabs of the concrete face.
At Campos Novos Dam, built in a narrow valley, the displacements of the superficial benchmarks showed an accentuated move towards the center of the valley. Log In Sign Up. It is worth repeating the technical contribution of Mr.
This problem was solved in further dams by changing the zoning of the fill material in the region of interest and new design of the perimetral joint, which had more than one sealing element and, as an additional defense line, when viable, a clay fill on barragebs perimetral joint.
Barry Cooke died in Such major infiltrations were associated to excessive displacements of the slabs in relation to the support plinth, whose perimetral joint was not designed to bear such displacement.
Flávio Alberto Crispel
On the d hand, the tensile joints seals of the slabs on the abutments regions should be capable to absorb the largest displacements resulting from the compression of the joints in the central area. Click here to sign up.
In his works, Cooke states that the principle of precedents must be followed, but it cannot be restrictive to the progress, either for the implementation of higher dams or for the adoption of more cost-effective solutions.
Remember me on this computer. Except for the Salvajina dam, the others were built in narrow valleys.
For this goal, studies should be developed with numerical models to estimate, from the very beginning of the design, the displacements and stresses in the dam. Wetting of all the materials and in every zone should be done, not only in the upstream third, as usual. Such width reduction would also restrict the area of the slabs dr torsional moments may occur.
REFLECTIONS ON NEW DESIGN OF VERY HIGH Concrete face rockfill dams | Ciro Humes –
Barry Cooke is invaluable. The results should receive continuous analysis to allow the necessary actions in the design and in the constructive methods. The rockfill embankment behavior is conditioned by several factors such as embankment zoning see Oliveira — Ref.
Compressive joints should be used in a way to allow the movement of the central slabs and relieve the compressive stresses among them. He received many awards for his brilliant professional performance, such as the Distinguished Engineering Alumnus Award, from the University of Berkeley — California, and the Terzaghi Lecturer offrom the American Society of Civil Engineers. Enter the email address you signed up with and we’ll email you a reset link. Figure 1 shows a map of horizontal compression stresses in the concrete face, considering the face without joints.
This prediction must take in place the geological-geotechnical features, the shape and topography of the valley concrdto the properties of available construction materials. Such failures motivated the abandonment of this type of solution for dams until when, with the development of heavy vibrating rollers for compaction of rockfill in layers, high rockfill dams with clay core started to be built. The basic principle stated by Cooke – Ref. This study aims at presenting a discussion on the main factors of development of these stresses.
His contribution in the development of this type of dam is invaluable, having participated of all Consultants Committees of CFRDs built in Brazil see Table 1 and practically of the construction of the main dams of this type around the world. Enricamento minimizations are so more expressive as barragns are the widths of the slabs. Cracks may occur in the concrete face; they would be tolerable since the embankment resists to the flow and the cracks can be easily sealed by placing fine material sandy silt.
Due to the result of the computations, double reinforcement mesh was adopted in large portion of the concrete face, contrary to the usual practice of using a single mesh in the center of the face.
These modifications were successfully introduced in dams built in Brazil and in the world; however, all of them with height below m the height of Foz enrocamentp Areia dam. All failures occurred in the central slabs caused from high compressive stresses, presenting an unknown behavior in such type of dam.
Compressive stresses in the concrete face without joint MPa Figure 2 shows a map of the compressive stresses in the concrete face considering compressible joints in the region of the face A notable reduction in the the compressive stresses could be observed.
However, it seems wnrocamento his confidence in the stability of this type of dam regarding its resistance to normal operation loads and to the action of eventual water dace led to adoption of some practical design criteria not totally applicable in very high dams built in narrow valleys, where stress levels extrapolated the already experienced values.
Also the thickness of the compaction layers should be adjusted, in function of the quality, gradation and shape of materials and of the type of compacting roller used.
This dam, built in open valley, has been showing excellent performance, and was a reference. The success of these dams, with heights of up to m Chicoasen Dam, in Mexicorestarted the construction of concrete face rockfill dams, attractive for their lower cost and shorter time of construction when local rain fall conditions are restrictive for soil compaction. This enroca,ento be an acceptable approach for CFRDs have intrinsic stability in function of the following features: Skip to main content.
Numerical model analyses ee done to predict probable displacements of the concrete face, which were then imposed to the slabs to obtain the respective stresses.